Fluid-pressure tool.



PATENTED MAYr 7, 190'?.

VA'-No. 853,201.

E. M. FABER. FLUID PRESSURE TOOL.

APPLICATION FILED JULYZQ, 1905.

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No. 853,201. PATRNTRD MAY 7, 1907.

' R. M., PARRR.

^FLUID PRESSURE TOOL. APPLICATION FILED JULYZQ, 1905.

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FRANK M. FABER, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO THE PITTS- BURGPNEUMATIC COMPANY, OF CANTON, OHIO, A CORPORATION OF NEW JERSEY.

FLUID-PRESSURE TooL.

Specification of Letters Patent.

Patented May '7, 1907.

Application filed July 29,1905. Serial No. 271,863.

To atl whom it. may concern: l

Be it known that I, FRANK M. FABER, a resident of Pittsburg, in thecounty of Allegheny and State of Pennsylvania, haveinvented a new anduseful Improvement in Fluid-Pressure Tools; and I do hereby deelare thefollowing to be a full, clear, and exact description thereof.

My invention relates to pneumatic tools for calking boilers and tanks,forming rivet heads, carving stone, etc. y

One of the objects of my invention is'to provide a device of thischaracter in which the full pressure of the air follows the pistonthroughout its entire stroke toward the tool, while at the same time toobtain a minimum recoil by causing the piston to come to rest graduallyby using the fluid which produces the stroke away from the toolcxpansively so that the pressure on the piston at theinstant that itreverses its motion is practically nil, and-lastly by causing thecompressed air to cushion on itself, so to speak, at the instant ol itsentrance to the cylinder.

To these ends my invention comprises, generally stated, a suitable bodylportieri having a cylindrical chamber therein, a piston in saidchamber, a valve chamber and a valve therein controlling ports leadingto said cylindrical chamber and to a reservoir into which air isadmit-ted simultaneously with its entrance to -the cylinder, whereby theair in said reservoir will act as a cushion to prevent i the too suddenapplication of pressure to the piston, and the drop in pressure at theinduction port is almost entirely compensated for by energy given out byfluid stored `in said reservoir.

` My invention l'urther comprises certain other new and novel features,all of which will be vl'ully hereinafter set l`orth and claimed.v.ltel'erriiig to the accompanyiiig drawings Figure is a longitudinalview ol my iniproved tool; Fig, 2 is a cross sectional view; Figs. 3 and4 are diagrammatic views which illustrate more readily the. arrangementof ports and which respectively show the valve in positions fordirecting the lluid pressure to I Produce the forwardv and returnstrokes ol' 'the piston; and ltig. 5 is a sectional View 'of a modiliedt'orm ol' part. ol' my valve mechan- Isin ln the drawings the numeral 2designates a suitable body which may be ol' any suitable form,'and whichis provided with the cylinder 3. Within the cylinder 3 is a piston 4fitting snugly within said cylinder. At the rear end of the body2 is thevalve shell or casing 5 to which is secure-d or formed integraltherewith the handle 6 for convenience in manipulating the tool. Withinthe valve casing 5 is the valve chamber 7 'which conto be understood aslimiting myself in any way to such a piston valve, or in fact anyparticular form of valve. This valve 8 is provided with the rings orcollars 9 10 '11 12 and 13, and saidvalve is adapted to move ber 7.Within the body of the valve 8 is Vthe .movable member 15, said plungerbeing prefiii 5.

gOriices 17 put the valve chamber 7 in communication with-the chamber 14and the main supply port 18 supplies the air tothe said chamber 7. Thepressure of the air in the chamber 14 normally acts to hold the valve inthe position indicated in the diagrammatic view Fig. 3, or at the rightend of the valve chamber.

to the cylinder 3 and a .port 20 leads from said valve chamber to thereservoir 21. Thls the handle 6, although I do not wish to limit myselfin any way to this location, as it may be located in the body of thetool' if desired. The handle 6 is provided with the plug 22 which closesthe reservoir 21`and this plug may be screwed up within the reservoir soas to reduce the size of said reservoir if desired.

The port 23 leads from the valve chamber which is at a distance somewhatgreater than the length of the piston 4 from the rear end of thecylinder 3. A branch port 23h may also connect the cylinder 3 with theport 23. The )ort 24 leads from the valvev chamber 7 to the front end ofcylinder 3 and the port 25 leads from the valve chamber 7 to a point'inthe cylinder 3 at a distance from its front end greater than thelcngth'of the piston 4. An exhaust port 2t leads from the valve 'chamber7 to the atmosphere. A second exhaust port 27 also leads from the valvechamber7 to the atmosphere. A port 2S leads from the 7 and enters thecylinder 3 at the point 23,-

tains a piston valve 8, although I do not wish freely back and forthwithin the said cham- 7 I chamber 14 within which fits the plunger orerably free from the head 16 of the valve cas- A port 19 leads fromthe'valve chamber 7 reservoir 21 may be conveniently located in y IOOvalve chamber 7 to the space 29 at the'right end of the valve 8 back ofthe collar 13.

For convenience in operating a throttle valve of any suitableconstruction should. be located in theport 18 so as to control thesupply of air to the'valve chamber 7.

The operation of my improved tool is as follows, and by reference to thediagrammatic views represented in Figs. 3 and 4 its operation will bemore readily understood: When the valve S and piston 4 are in positionshown in' Fig. 3, fluid pressure admitted through the port 18 enters thechamber 14 through the orifices 17 and holds the plunger 1,5 firmlyagainst the head 16, and forces the valve to the limit of its stroketoward the right, as clearly shown. As the orifices 17 are always incommunication with' the feed supply pressure admitted to the chamber 14the valve is held inthe position shown in Fig.

p 3 until a superior force is introduced'to drive the valve toward theleft or into the position shown in Fig. 4. Fluid pressure alsosiinultaneously enters the cylinder 3 and the reservoir 21 through ports19 and 20 respectively, the piston 4 now starting on its for wardstroke. By permitting the Huid pressure to enter the reservoir andcylinder in this manner l'gain a two-'fold result: first.

entering the reservoir will act as a cushion to prevent the too suddenapplication of prespressure at t sys sure to the e induction port 13which would otherwise be marked as 'the piston reached the completion ofits forward stroke?, is almost entirely compensated for by energy. givenout by fluid stored in the reservoir. The piston advances then underpracticallyinitial pressure until it strikes the tool 30. As 'the piston4 advances the fluid in front thereof exhausts throughthe ports 24 and27. Just before reaching the end of its forward stroke the piston passesthey port 25 and admits fluid pressure against the opposingI annularsurfaces of the rings or collars -`12 and 13. ThelV area of the annularsurface of the collar 12 being larger tha-n that of 13 the`introcluction of fluid pressure between them tends to throw the valvetoward the left and'by making the areas of these rings or collars suchthat the difference-in their areasis greater than the cross area of theplunger 15, the tendency exerted by fluid pressure in the chamber 14 isovercome and the valve is thrown to the left.

The resultof moving the valve toward the left is 'as follows: first, thecollar 10 closes communication between the induction port 18 vand thereservoir 2l and at or about the same instant the collar 11 closes theport 19; second, the collar 9 passes beyond the port 28 and admipressure from the reservoir 21 to the space 29 and against the 'end ofthe valve or the collar 13, thus acting to complete its throw; andthird, the collar 11 passes and piston; and second, the drop in 1 'theport 28 opens and admits pressure from lmovement is required.

opens port 23, allowing fluid ressure 'in the cyhnder 3 to exhaustthrong ports 23 and 26. At or about the same instant the collar 9 passesthe port 24, when the parts will all have assumer the ositions shown inFig. 4. Fluid pressure in tfie reservoir 21 now passes Athrough the port20 into the annular space between the collars 9 and 10, thence throughthe port 24 to the front end of the cylinder.

By admitting pressure from the reservoir to the space 29 a completethrow of the valve under all conditions is insured. Should the port 28be omitted and the movement of the valve toward the left be entirelydependent on pressure 'admitted through the port 25 the hammer would notstart when standing vertically, the forward end down. When in thisposition the piston drops to the front end` of the cylinder, as shown inFig. 4. If now the throttle should be opened the valve would be thrownto the 'right by pressure in the cylinder or chamber 14, as before, whenpressure would pass through the cylinder and into the space 7 by port 25starting thel valve toward the left. The moment, however, the port 23 isopened pressure in the cylinder and space 7 yexhausts into theatmosphere through the exhaust 26 and the valve is thrown to the wrightby pressurein 14 as already explained. the recoil is greatly modied,since the fluid.

So then under the conditions just described, the valve would not makeits complete stroke but would stop entirely or flutter at the point ofits throw when exhaust begins. Accordingly l so proportion the partsthat the reservoir to the space 29 before the exe haust begins, and as lmake thefdiameter of the ring. 13 greater than the diameter of thechamber' 14, the valve willbe thrown completely over under allconditions and be held rigidly in place until the normal reversel Thepiston having completed its forward stroke, and the valve being intheposition shown in Fig. 4, the action of my hammer continues as follows:1 Fluid pressure enters the front end of cylinder 3 and actingexpansively starts the piston on v its backward or vreturn stroke. iWhen the piston passes port 23b 'compression begins and gradually bringsthe piston to rest. When r lthe piston passes entirely beyond 23a thefluid pressure in th e reservoir, the front end of the chamber 3, thespace 7a and the end 29 of the vvalve chamber, exhausts through-.ports23a, 23 and 26. .The fluid pressurein spaces 1 7 a and 29 being nowreduced to that of the atmosphere, the fluid pressure in cylinder 14 atonce throws the valve'into. theposition shown in Fig. 3, when the cycleof'o'peration's just described is rapidly repeated, n 1 lt is evidentth, t by properly proportionin r the volume of the reservoir to volumeof cylinder the'fluid pressure used for producingF the return stroke ofthe piston may .be ex panded down to any pressure desired at'ftlie I' ofexhaust As described above the valve is held in the -by= fluid pressureadmitted from the reservoir through the passage-Way 28 to the space inthe valve chamber It is evident that by lsuitably decreasing the volumeof the reservoir the fluid pressure therein may during the return strokebe expanded down to a pressure desired before the piston 4 passes andopens the exhaust port 23a; consequently the relative volumes in thereservoir' andicylinder may be so proportioned that the pressure in thereservoir maybe expanded to a point Where the pressure in the chamber 29will not be sufficient to nold the valve in the position shown in Fig. 4against the'constant pressure in the chamber 14. Under these conditionsthe valve will be thrown into the position shown in Fig. 3 and airadmitted through port 19 to produce the forward stroke before thepister` 4, While on its return stroke, passes the exhaust port 23, andconsequently the length ofi stroke may be' reduced to any desiredvextent by 'a suitable reduction of volume of reservoir.

In Fig. 5 I have shown a niodiiied arrangement of the plunger andchamber to receive the fluid pressure and hold the valve in the positionsnown in Fig. 3. In this case the chamber4() is formed in the end orhead of the valve chamber and the Huid pressure con`- fined thereinexerts a continuous tendency to move the valve in a given direction ortoward the right, as shown in the accompanying drawings.

Itis obvious that otner methods than those described may be employed foractuating the valve without departing from the spirit of my' invention,and that valves of different types -eoininunicatiifig with saidcylinder,

ina-y be employed instead of the one illustrated. Furthern'iore, it isobvious that the location of the reseivoir may be changed and 'thatvarious other changes mav be made in the forni, proportions and'location of parts 'and still come Within the scope of my invention.

What I claim is:

1. In a fluid pressure operated tool, a suity able body portion having acylinder, a piston, a valve controlling the ports to said cyl-` inder,and a reservoir communicating with said cylinder, and means foroperating said valve to alternately connect said reservoir with thefluid pressure supply and with said cylinder. j r

2. In a fluid pressure tool,'a suitable body portion having a cylinder,a piston, -means l'or reciprocating said piston, a reservoir and meansfor varying the volumeA of said reser voir.

portion having a cylinder, a piston, a reservoir, a valve controllingports leading to said cylinder and reservoir, and means for ad- 3. In aHuid pressure tool, a suitable body' .y s

moving in both directions, and a branch-port l `i init-ting fluidpressure simultaneously to said cylinder and reservoir.

4. In a fluid pressure tool, a suitable body portion having a cylinder,a piston, a reservoir, a valve controlling ports leading to saidcylinder and reservoir, and means for moving said valve by liuidpressure from saideylinder and said reservoir. v

5. In a fluid pressure tool, asuitable body having a cylinder, a piston,a reservoir, a

A valve controlling ports leading to said cylinder and reservoir, andmeans for moving said valve by fluid ressure from said reservoir.

6. In a Il ui pressure tool, a suitable body portion having a cylinder,a piston', a reservoir, a valve controlling ports leading to saidcylinder and reservoir, and a eating with said reservoir an 4carryingfluid .pressure to the valve chamber tooperate said valve.

7. In a fluid pressure tool, a suitable body portion having a cylinder,va piston, a reserort conimunivoir, a valve controlling ports leading tos aid cylinder and reservoir, means lfor carryinor fluid ressure fromthe forward end of sai cylin er to the valve chamber and from saidreservoir to move said valve.

8. In a fluid pressure tool, a suitable body ortion having a cylinder, apiston, means' iston, a handle,` and a or reciprocating said ecommunicating with reservoir in said han said cylinder. Y

9. In a fluid pressure tool, a suitable body portion having a cylinder,a piston, a valve the movement of said piston,

controlling having a chamber therein' conisaid valve,

niunieating with the fluid (pressure supply, a

plunger in said last name chamber, collars of different areas at voneend of said valve, means for admitting fluid pressure to the spacebetween said collars, the difference in areas of said collars beinggreater than the area of said chamber, whereby said valve is movedagainst the pressure Within .saidf chamber.

10. In a fluid pressure tool, a suitable body portion havin a cylinder,a iston therein, a valve control ing ports lea ing to opposite ends ofsaid iston, and a port'conducting fluid from-said cylinder to the valvechamber and thence t the atmosphere and beyond which the entire pistonpasses when moving in both directions.

11. In a fluid pressure tool, Va suitable body portion having acylinder, a reciprocating piston therein, a valve chamber, a, valvewithin said of said piston and a main exhaust passage controlled by saidvalve, a main exhaust port connecting the passage with the cylinder at adistance from its rear end and beond which the entire piston passes whenchamber controlling the motion ISO 12; 'In a fluid pressure tool, asuitable body portion having e cylinder, a pistoue reser- Voir, a valvelfor controlling ports leading to said cylinder and reservoir, and meansfor holding saidyalve in one position b y pressure from said reservoir.

13. In a pneumatic pressure tooLe suitahle body having a cylinder; a'reciproeating piston Within the cylinder, e reservoir supplying fluidpressure tothe cylinderto force the piston in one direction, and meansfor increasing or diminishing the volume of the reservoir to produce acorresponding increase or reduction in length of stroke of the piston.15 In testimony whereof, I the said FRANK M. y FABER have hereunto setmy hand,

i l FRANK MFABERQ VVitne-sses A l ROBT. D. TOTTEN, I ROBER'r C. Tonnie.'

